The buddha.dll file is a dynamic link library associated with the game’s engine and, in many retail versions, the digital rights management (DRM) system. When you launch Hitman Absolution, the executable searches for this file to initialize core game functions. If it is missing or corrupted, the game will fail to start, often displaying a popup stating that the program can't start because buddha.dll is missing from your computer.
Here's a rundown of the features related to the "File Buddhadll" in Hitman: Absolution: file buddhadll hitman absolution